Some rainfall stats for this July. Source, with acknowledgements. 🙂🙂🙂
JULY - DRY
Taking an updated look at dry Julys, as so far (up to yesterday) this July is the driest on record, with only 4.04mm (England and Wales). This July will finish top of the list below.
Original TAW research
As usual we are using the Met Offices EWP records, and split the indexes/rankings up into equal thirds, good/average/bad etc.
The top 20 driest Julys since 1930 are -
2022 - 22.6mm
1976 - 23.7mm
1955 - 26.1mm
1999 - 26.3mm
1935 - 27.1mm
1984 - 28.6mm
1970 - 30.1mm
1982 - 33.9mm
1979 - 34.1mm
1952 - 34.7mm
The next top ten - 1995, 1989, 2006, 1983, 2018, 2016, 1996, 1971, 1994, 1948
ENSO
-1 was El Nino
- 5 were La Nina
- 12 were Neutral
A clear signal there that an ENSO neutral phase is more likely to produce a dry July. El Nino isnt most conducive for a dry July.
MJO – Only phase 6 supposed to be a dry phase although 4 and 8 are benign.
Of the qualifying years (1974 onwards) phase 1 = 4, 2 = 4, 3 = 5, 4 = 5, 5 = 4, 6 = 3, 7 = 4, 8 = 3 . Well clearly this doesn’t support the dry phase theory. Thats a pretty even scatter.
JULY TEMPS
- 1 was also cold (1970)
- 3 were average
- 16 were warm (no surprises)
TAWs JULY INDEX
- 0 were bad
- 3 were average
- 16 were good
As we would expect, a dry July is likely to be good and warm.
August
- 1 was cold
- 7 were average
- 12 were warm
- 8 were dry
- 8 were average
- 4 were wet (1977, 1952, 1971, 1948)
Dry Julys then are likely to turn wetter in August, but unlikely to be too wet? They also are unlikely to have a cold August.
TAWs AUGUST INDEX
- 4 following Augusts were poor (1977, 1999, 1971, 1948)
- 5 were average
- 11 were good
Some years can flip to cold and wet, but generally a dry July leads to a good August, with only a 20% chance of it being poor.
Originally Posted by: Hungry Tiger